The article is devoted to the improvement of the design of a desalination solar plant for more efficient and economical production of desalinated water due to intensive evaporation of the boiling ...solution, reduction of energy losses to the external environment and the absence of the need for continuous adjustment of the direction of the light-receiving part of the solar plant. The expedient parameters of the angles of inclination of the optical axis of the lens relative to the azimuth and the incidence vector of solar radiation, which ensure high performance of the solar plant, were experimentally substantiated. The use of a solar collector equipped with an additional heat accumulator will allow water to be supplied for desalination at a temperature of more than 50 °C in sunny weather, and at a temperature of 33–36 °C in variable cloudiness, which will help to increase the efficiency of the desalination solar plant. The presence of a heat accumulator and a layer of thermal insulation under cloudy conditions allows maintaining the operating water temperature at 33–36 °C 4.4 times longer than without them.
The article is devoted to the disclosure of the effect on the vital activity of cyanobacteria by changes in the nutrients in the chemical composition of artificial aquatic biotopes. The research ...results allowed us to establish that the dissolution of complex mineral fertilizer (nitrogen, phosphorus and potassium) in the range of up to 10 g/L contributes to the active development of cyanobacteria, which is accompanied by complete binding of mineral additives and absorption of oxygen. The addition of fertilizers in the amount of more than 1 g/L contributes to a sharp increase in the growth rate of the cyanobacteria population, which provokes the conditions for the blooming of the solutions. Enrichment of the nutritive base of biotopes ensures rapid growth of biocenosis and accelerated consumption of dissolved substances. The recorded average absorption rate of phosphorus reached more than 17 g/(L*day), and nitrogen – 30 g/(L*day). The formation of sediment and foam in the test vessels was associated with the depletion of nutrients and the death of hydrobionts. This phenomenon can serve as an indicator of oxygen decrease in the water. The results of the experiment confirmed the ability of cyanobacteria to transform nitrogen and phosphorus dissolved in water into bound organic forms with high intensity. This opens up the prospect of creating biological methods and means of wastewater demineralization.
The article is devoted to solving the issue of ensuring the efficient operation of aeration equipment in the conditions of shallow water bodies with an average depth of only a few meters. The article ...offers a technical solution for reducing the size of airlift aerators and increasing their performance by creating a recirculation movement of water inside the unit. With the help of a laboratory model, it was established that the dynamics of oxygenation of water in the pool with the help of a recirculating airlift is subject to a logarithmic dependence on the size of the flow regulator. It was possible to increase the oxygen concentration in the pool by 2.6 times within three hours as part of the simulation. The rate of water oxygenation was much higher than for a conventional airlift of the same size. The offered cost-efficient aeration unit, which uses wind flow as an energy source, can be used for fish farms and other applications.
The article is devoted to substantiation of parameters of water body aeration technology at high, as well as low, air temperatures. As a result of studies, the design of the water aerator based on a ...two-stage airlift has been improved. A study of its physical model has been conducted. The cost indicators of the set-up and its components have been obtained. It has been established that at various design parameters, the proposed scheme of operation allows to oxygenate water more effectively when compared to conventional design. A new type of water aerator based on two-stage airlift has been proposed. The linear dependence of the dynamics of the aerator flow rate on the supply of compressed air by the compressor, as well as the logarithmic dependence regarding the water oxygenation have been established. The indicator of effective rate, which allows for evaluating efficiency of water body oxygenation has been substantiated. The study results open the possibility of using an aerator with improved design to prevent eutrophication of water in open water and industrial reservoirs, e.g. in construction.
